Atomic layer deposition of hafnium oxide thin films from tetrakis (dimethylamino) hafnium (TDMAH) and ozone

Hafnium oxide (HfO 2 ) thin films were synthesized from tetrakis(dimethylamino) hafnium (TDMAH) and ozone (O 3 ) by atomic layer deposition (ALD) on 200 mm silicon wafers. Gradual saturation was observed for TDMAH exposure pulse. However O 3 showed better saturation behavior for O 3 exposure. Yet, 100% step coverage was achieved for ~100nm trenches with aspect ratio of 35. Temperature dependence of the deposition rate was studied at susceptor temperature from 160°C to 420°C. The lowest deposition rate was observed at 320°C. Mercury probe measurements indicated the dielectric constant increased from 16 to 20 as susceptor temperature increased from 200°C to 320°C. Selected comparisons with tetrakis (ethylmethylamino) hafnium (TEMAH) were also made.